Pump for cutting oil



Jan. 3, 1950 J. SUNNEN 2,493,467

PUMP FOR CUTTING OIL Filed Dec. 15, 1947 INVENTOR. JOSEPH SUNNEN Patented Jan. 3, 1950 PUMP FOR CUTTING OIL Joseph Sunnen, Clayton; Mo. Application December 15, 1947, Serial No. 791,860

4 Claims. (Cl. 103 108) This invention relates to oil pumps generally,

and more particularly to pumps for pumping used honing or cutting oils.

The designing of such pumps, previously, presented considerable difficulty in that the abrasive particles carried by the oil soon'cut out any bearing surfaces, such as between a piston and cylinder, and even caused difficulty with the use of centrifugal pumps.

Such pumps must be extremely durable. and rugged in their construction as they are required to operate continuously for long periods of time to pump the cutting or honing oil which may contain large quantities of dirt and grit of varying size and is not usually convenient or desirable to operate the pump at high enough speeds to develop the desired pressure from a single stage centrifugal pump of reasonable size.

Accordingly, the main object of the invention is to provide an oil pump of extremely simple and rugged design capable of pumping used cutting oils containing grit and metallic particles.

Another object of the invention is to provide a. multi-stage pump of the general character indicated without any close fits or wearing surfaces in the balance of the oil which is being pumped.

Another object of the invention is to provide a pump of the above described character with means to rub its bearing surfaces with oil from which all abrasive particles have been removed and to prevent the danger of unpurified oil reaching the bearing.

Another object of the invention is to provide a multi-stage centrifugal pump comprising only a substantially cylindrical casing and a single moving part or rotor of the simplest possible construction.

Another object of the invention is to provide a centrifugal pump having adequate bearing for stable rotation of a rotor, yet in which wear due to abrasive particles in the pumped oil will be reduced to a minimum.

Still another object of the invention is to provide a pump which is durable in operation, cheap and simple to manufacture, and economical i operation.

While the scope of the invention is defined in the appended claims, the following detailed descriptlon, when taken in connection with the 2.0- 4

companying drawing, W111 explain the invention, its construction, and use.

. Fig. l is a side elevational view of a pump which embodies the invention.

Fig. 2 is a side elevational view of the same at right angles to Fig. 1.

Fig. 3 is an enlarged longitudinal section taken along line 33 of Fig. 1.

Fig. .4 is a partial longitudinal section taken along line 4-4 of Fig. 1 and showing in detail the needle valve assembly and discharge outlet.

Fig. 5 is a top view of the pump with the sheave wheel removed and showing a portion of the oil feed system, and

Fig. 6 is a top view of one of the impellers.

vAs shown in the drawings, the preferred embodiment of the invention has a body II with a longitudinal bore including a main cylinder l2, which is open at the bottom, as at l3, and which includes reduced portions [4, l5, and IS, the latter forming a journal bearing for a pump shaft H. The reduced portion l5 may or may not be origi- 'nally formed of the same diameter as the reduced portion !6 but in any case, it should not be considered. as a bearing because its utility as such is soon destroyed by the abrasive action of the grit in the cutting oil which is being pumped. The passage between the reduced portion I5 and the shaft ll is that of a flow restricting device which permits only a small amount of oil to escape from the upper end of the chamber I 4 to insure the supply of a. restricted quantity of oil to the lower end of wick 36. Centrifugal impellers !8 are carried by shaft I! within the cylinder l2. Amxed to the other end of the shaft I! is a sheave H! for receiving a belt (not shown) to rotate the shaft I! and its impellers l8. Shaft I1 is carried by an end bearing 20 on body H against which rests a shoulder forming boss 2i on sheave ii).

A threaded cross passage 22 intersects the re duced portion M of the longitudinal bore and forms an oil discharge opening 23 at its right end (Fig. 4) for attachment of an oil feed line which is not shown. Contained within the threaded cross passage is a control. needle valve 24 having a threaded enlargement 25 and knurled head 26. The control needle valve 24 is locked into an adjusted position by a wing nut 21. A valve seat 28 also is threadedly seated in passage 22 into which the control needle valve acts to control the 7 rate of oil delivery.

Impellers I8, of which there are three in number shown in the preferred embodiment, are disk shaped, each having abevel 29 and a pair of aligned diagonal passages 30. A counterbore 3|, in the under surface of each impeller, intersects 7 each passageand forms an inlet opening around shaft I1. Each impeller I8 is secured tothe shaft [1 by set screws 32. It will be noted that these impellers are substantially operated from each other in the main cylinder l2 so that the walls of the cylinder between the rotors acting with the viscosity of the oil which is beinglpumped provide sufiicient friction to substantially slow down the rotation of the oil after it leaves the outlet passage of the rotor and before it enters the inlet passage of the next rotoror the outlet passage of the pump. It will be understoodby those skilled in the art that the pressure developed by a centrifugal pump cannot be delivered at the center of rotation until the rotative speed of the fluid is reduced. I accomplish this by the friction of the cylindrical bore l2 without the insertion of any bafiles, 'volutes, or any members in addition to the rotor and the cylinder. v

. A cross duct 33 extends between the shaft journal'bearings l5 and 16 above the oil discharge opening 23. .The restricted intermediate portion pressure from passage I l flows through the lower {g under pressure above each impeller l8 leaking back to its inlet side stabilizes the shaft I! as well as does the journal [5 and bearing 20. 7

After the oil is pumped through each of the impellers bit is rotating at the same speed as the impeller 18. This rotation of the oil is slowed by the frictional forces of the wall between each impeller l8 acting upon the rotating oil, whereby the oil is applied to the inlet of the next impeller [8 which has been slowed and hence under increased pressure. The space between each impeller is not critical but only must be of sufficient distance to allow the oil which has been pumped by lower impeller l8 to ;be slowed down so that the pressure .near the inletfloftheneXt impeller will be approximately that of pressure adjacent ,the walls of the body.

, .Various changes may be made in the details of 1 "construction, within the scope of the appended claimS WithOut departing from the spirit of the invention. Parts of the invention may be used without the whole and improvements may ber added while retaining some or all of the advanjournal l5 and'then outthrough the duct 33, An

oil bore 35 is fashioned longitudinally into the body H from its upper end and intersects with duct 33. This oil bore 35 holds'a wick 3B which may be in the form of the ordinary wire held cotton pipe cleaner. The upper portion of this wick 36 lies in a slot 31 which extends across the face a 'of the bearing 20 on the body H- Thus, clean oil isfed to the bearing 20 and journal l6 by.capillary attraction. Abrasive action of the grit and metallic parts in the pumped oil willwear out any journal action. at [5 but upper journal Hi and bearing 2!! will remainltrue .becausethe lubrication which is fed to them by the wick 36 is clean and therefore there will be no appreciable wear at these points. 1

The shaft I1 is stabilized against the belt forces by bearing 23 and journal l5 which, accordingly, should fit closely. However, the restricted portion I 5' and the impellers I8 need not fit close and their clearances may be increased up to a certain point during operation of thepump by the abrasive action of the particles in the oil. Ultimately, little or no further wear will occur at these points because of the clearances.

tages of the invention. I claim: 1'. In an oil pump,

vertical bore therein, af'shaft mounted in said bore, an impeller carried by said'shaft saidimpeller having an inlet near the center at itslower end and an outlet near the periphery at its upper end, a discharge outlet in said body member above said impeller, a bearing for said shaft in the upper part of said body" member, a second bearing for said shaft above said, first bearing and. an oil return outlet to permitfthe escape of oil under pres sure escaping 'fromthe upperien'd or said first bearing. .1

2., In anoil pump, a body member having a vertical bore therein, a shaft-mounted in said bore, an impeller carried by said shaft, said impeller having an. inlet near the center atits lower end, and an outlet near the periphery at its upper end, a discharge outlet in said body member above said impeller, a bearing for said shaft in the upper partof said body member, a second bearing for'said shaft, above said firstbearing, an oil return outlet to permit the escape of-oil 'under pi'essure escaping from the upper end of said first bearing, and a wick having ,an end positionedto receive oil escaping-from. said firstbearingand having its upper endpositioned to supplyoil to the upper bearing by capillary feed only.

3. In an oil pump, a body member having a bore therein, a shaft 'mounted in said bore, a driven membermounted on said shaft above said body member, an impeller carried by said shaft, said impeller having an inlet opening near the center at'its lower end and an outlet near the periphery at its upper end, a discharge opening in saidbody member above said impeller, affirst bearing for said shaft in the upper part of said body member,

The peripheries of the impellers l8 need not be a in close bearing contact with the wall of the cylinder and even if originally'made close fits at these points, they would not remain so on account of thewearf However, there is littleor 'no tendency. to flow across the periphery of the impeller from the outlet sideto the inletside because thespeed of rotation .Of the oil is substantially the same at each point so that there is likely to be aconstant flow of grit through the spacebetween the cylin-' der and the periphery of the impeller. The oil a second bearing for said, shaft above said first bearing, an oil return outlet above said firstbearing to permit the escape ofoil under pressure escaping from the upper'end of said first, bearing,

a thrust bearin'g'ab'ove said'second'bear 'ing formed by said driven member and the upper end ofsaid body memben'and a wick having an end positioned to receive oil escaping from said first bearing and having its upper end positioned to supply oil to the second bearing and said thrust hearing. by capillary feed only.

4. A pumpfor cuttingoils comprising a, body having, a longitudinal how, an oil intake port and an oil discharge port therein, said bore hav- 'a :body "member having a ing an enlarged portion at its lower end, and a shaft rotatably supported in the upper end of said bore by spaced upper and lower bearings, drive means aifixed to said shaft and having a thrust bearing against the upper end of said body, a plurality of impellers aflixed to said shaft and rotatable in said enlarged bore, and a bearing lubricating system having an oil discharge opening communicating with said bore above said lower bearing, a second bore connecting said thrust bearing with said oil discharge opening, and a wick in said second bore to apply oil to said upper bearing and said thrust hearing by capillary feed only.

JOSEPH SUNNEN.

& REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name- Date 738,244 Roth Sept. 8, 1903 795,595 Erickson July 25, 1905 819,986 Ellis May 8, 1906 1,220,403 Doble Mar, 27, 1917 1,713,427 Earl May 14, 1929 FOREIGN PATENTS Number Country Date 207,248 Germany Jan. v8, 1939 

